Modification of hemp shiv properties using water-repellent sol–gel coatings

For the first time, the hydrophilicity of hemp shiv was modified without the compromise of its hygroscopic properties. This research focused on the use of sol–gel method in preparation of coatings on the natural plant material, hemp shiv, that has growing potential in the construction industry as a thermal insulator. The sol–gel coatings were produced by cohydrolysis and polycondensation of tetraethyl orthosilicate (TEOS) using an acidic catalyst. Methyltriethoxysilane (MTES) was added as the hydrophobic precursor to provide water resistance to the bio-based material. Scanning electron microscopy (SEM) and focused ion beam (FIB) have been used to determine the morphological changes on the surface as well as within the hemp shiv. It was found that the sol–gel coatings caused a reduction in water uptake but did not strongly influence the moisture sorption behaviour of hemp shiv. Fourier transformed infrared (FTIR) spectroscopy shows that the coating layer on hemp shiv acts a shield, thereby lowering peak intensity in the wavelength range 1200–1800 cm−1. The sol–gel coating affected pore size distribution and cumulative pore volume of the shiv resulting in tailored porosity. The overall porosity of shiv decreased with a refinement in diameter of the larger pores. Thermal analysis was performed using TGA and stability of coated and uncoated hemp shiv have been evaluated. Hemp shiv modified with sol–gel coating can potentially develop sustainable heat insulating composites with better hygrothermal properties

Remembering Democracy in the Debate over Election Reform

In FEC v. Wisconsin Right to Life, Inc., the United States Supreme Court held that the federal Bipartisan Campaign Reform Act violated the First Amendment right to free speech because the statute restricted a form of political speech known as issue advocacy. In attempting to protect this right from government intrusion, however, the Court improperly excluded considerations of democracy from its free speech analysis. The opinion consequently misrepresented the nature of the right to free speech for two independent but related reasons. First, because preserving a well-functioning democracy is the primary reason free speech is protected, the right to free speech does not exist when it is not justified by-nor when it conflicts with-the interest in preserving a healthy democracy. Second, an inductive review of American history and law shows that democracy is an independent right. The Court was therefore responsible for determining whether the political speech in question conflicted with the right to democracy and adjudicating between these two rights. By explicitly deciding not to weigh the impact that issue advocacy has on democracy, the Court set the dangerous precedent that courts can decide free speech cases without considering whether the speech in question tramples on the interests and rights that define it and determine its scope

Análisis del mercado de órganos para trasplante: evaluación de la introducción de incentivos en la Argentina

Since its expansion in the late 60s to the present the amount of transplant performed has increased slowly but steadily. However, the demand for organs to be transplanted has risen at a considerably higher rate creating a widening gap between the demand and supply for organs. In several cases, average time on the waiting list even exceeds life expectancy of the patient who needs the transplant. The aim of this paper is to evaluate the introduction of monetary incentives in the market for kidneys and livers. In theory, these incentives would significantly increase the supply. Literature that refers to the statistic value of life and other tools of economic analysis will be used so as to estimate the equilibrium price of organs that will eliminate the current gap and save lives without excessively increasing the total cost of transplant surgery

Organizaciones gestionadas por refugiados como socios en el desarrollo

La incorporación de organizaciones gestionadas por refugiados a programas de desarrollo, potencialmente como socios ejecutores, es una forma de capitalizar las habilidades de los refugiados, de alcanzar a los que no están afiliados a ninguna organización internacional y de comenzar a cerrar la brecha entre ayuda y desarrollo que existe en las situaciones de refugiados prolongadas

Book review: diasporas, development and peacemaking in the Horn of Africa, edited by Liisa Laakso and Petri Hautaniemi

The volume presents a stimulating overview of the varied positions, such as peacebuilders, investors, and civic members, that members of diasporas hold, as well as extant gaps related to diasporas such as theoretical frameworks and host country institutional incorporation and engagement. This is an enriching book, writes Evan Easton-Calabria

Geometry and Construction of Ribbed Vaults: Choir of the Braga Cathedral

The study takes into account the choir vault of the Braga Cathedral as a paradigmatic example of the evolution process of Portuguese multi-ribbed vaults. In fact, it can be considered the first step of the features transmigration occurred throughout the Iberian Peninsula and evolved in a continuous transformation from building to building. The stylistic/typological interpretation, as it is often conducted, is not exhaustive for what concerns stone vaults: conception and meaning of subtended space, construction processes and methods of form definition are essential to read the structure. The study of late Gothic ribbed vaults fits into the research field of structural interpretation from the perspective of “form generators”: this type of construction realizes a strict correspondence between the two aspects, materializing system stress lines through the rib. We analyze one of the first work attributed to Joao de Castilho. The cabeceira of the Braga Cathedral clearly shows traits inherited from ribbed vaults with petal flowers design, typical of Seville and Burgos areas. The various aspects that define the shape are mutually interpenetrating and inseparable: geometric definition, surfaces analysis, underlying spatiality and, finally, the way in which these three are connected to the constructive process. The possibilities of the ribbed lattices are achieved here by a sort of "sphericity research", as if to mediate Gothic reminiscences with the desire to absorb new Renaissance influences. The spatiality research is not an end in itself but can be considered, at the same time, result and assumption of precise constructive methods, giving rise to a logical sequence of steps connected to the building site economy

Experimental tests on a pre-heated combustion chamber for ultra micro gas turbine device: air/fuel ratio evaluation

Current portable power generators are mainly based on internal combustion engine since they present higher values of efficiency comparing to other engines; the main reason why internal combustion engine is not convenient for micro power generation (5 - 30 kW) is because of their heaviness. Micro and ultra micro gas turbine devices, based on a micro compressor and a micro turbine installed on the same shaft, are more suitable for this scope for several reasons. Micro turbine systems have many advantages over reciprocating engine generators, such as higher power density (with respect to size and weight), extremely low emissions and few, or just one, moving part. Those designed with foil bearings and air-cooling operate without oil, coolants or other hazardous materials. Micro turbines also have the advantage of having the majority of their waste heat contained in their relatively high temperature exhaust. Micro turbines offer several potential advantages compared to other technologies for small-scale power generation, including: a small number of moving parts, compact size, lightweight, greater efficiency, lower emissions, lower electricity costs, and opportunities to utilize waste fuels. The object of this study is the experimental tests on a stand-alone gas turbine device with a pre-heated combustion chamber (CC), to validate the fuel consumption reduction, compared to an actual and commercial device, used on air models

The structural tree: new experimentation with reinforced stone

Starting from the reinterpretation of the natural forms that recurs in the consolidated shapes of historical buildings, the research proposes the umbrella vault as isolated selfsupporting cover. The research outcome, defined with the term "structural tree", can be considered as an extreme experimentation of the cooperation possibilities between natural stone and steel reinforcement. The idea arises from the observation of fan vaults in which appears an isolated support: its static behaviour works, of course, because of the presence of an opposite structural portion. In this case, on the contrary, there are no lateral supports but it arises as a self-referential element, while the task of restoring the structural balance is left to the upper reinforcement that allows a free composition of the "tree" without static constraints. The study is based on a formal research that combines the possibility to create serial and repeatable compositions with the achievement of an ideal static equilibrium configuration of the stone structure that considers the collaboration between the voussoirs and the upper reinforcement. The steel structure is not assumed as a pre-tensioned reinforcement, like in the other prototypes, but as a passive reinforcement to recreate the compression condition of the arch, usually generated by the opposing forces belonging to the two symmetrical halves

Resilient hemp shiv aggregates with engineered hygroscopic properties for the building industry

This study focuses on the surface treatment of an extremely hydrophilic natural plant material, hemp shiv, using a functionalised silica based coating to provide hydrophobicity while retaining its moisture buffering ability. The chemical composition and physical structure of bio-based materials results in their extremely hydrophilic behaviour. In this work, a simple one step coating process was used to enhance the water-repellence of hemp shiv without compromising its ability to adsorb and release moisture. The coating modified the morphology and surface roughness of hemp shiv providing a hydrophobic surface having a water contact angle of 118° and reduced the bulk water absorption by 250% over 24 h. Mercury intrusion porosimetry (MIP) showed that the treatment refined the pore size distribution of hemp shiv, reducing the size of larger pores but not completely blocking the smaller pores thereby allowing hemp shiv to buffer moisture. Fourier-transform infrared spectroscopy (FTIR) revealed the chemical composition was modified by the coating, reducing the hydroxyl groups. Hemp shiv aggregates treated with functionalised silica based coating show potential for the development of robust lightweight building materials with enhanced hydrophobicity

Implantación de un procedimiento para la atención de menores en situación de riesgo en el municipio de Gandia: 'Un reto para la consecución de Buenas Prácticas en el ámbito de Familia e Infancia'

El marco jurídico vigente en materia de protección de menores define las competencias de los Servicios Sociales Municipales en la prevención, detección e intervención en todos aquellos casos en que existan menores de 18 años, que se encuentren en situación de Dificultad Social (riesgo leve), Desprotección (riesgo moderado, grave y desamparo) y/o Conflicto Social. La práctica diaria y la complejidad en la atención al usuario y/o familia, hacen necesaria la elaboración de circuitos y el desarrollo secuencial del proceso que se pretende llevar a cabo desde cualquier servicio o programa. Por lo tanto, el manual de procedimiento de atención a menores en situación de riesgo consiste en un documento técnico que define el marco, el procedimiento de actuación a seguir, los profesionales que lo realizan y los criterios e instrumentos técnicos a utilizar por este servicio en la intervención con los menores y sus familias. En definitiva, se trata de una herramienta de trabajo de uso generalizado por todo el equipo de Servicios Sociales de Atención Primaria del Ayuntamiento de Gandia que ha sido posible gracias al esfuerzo y al trabajo de los profesionales y de su experiencia en estos últimos años.The current legal framework as regards protection of minors defines the competences of Municipal Social Services in prevention, detection and intervention in all cases involving children under 18 who are in a situation of Social Difficulty (slight risk), Vulnerability (moderate, serious and neglect) and/or Social Conflict. Daily practice and the complexity in care for users and/or families make it necessary to prepare circuits and sequential development of the process intended to be carried out through any service or programme. The procedure manual for care for minors in a risk situation therefore consists of a technical document defining the framework, the action procedure to be taken, the professionals carrying this out and the criteria and technical instruments to be used by this service in intervention with minors and their families. This is in fact a working tool for general use by all the Primary Care Social Service teams at Gandia Council, which has been possible thanks to the efforts and work done by the professionals and their experience over the last few years